The present invention relates to piston compressors, more particularly to a means of protecting a piston surface, and a head mounted valve of the piston compressor from wear due to repetitive contact between the two parts. Alternatively, when the compressor uses a piston mounted valve, the present invention provides a means of protecting a head surface and the valve from wear due to repetitive contact between the valve and the head. The present invention also acts to reduce operating noise of the subject compressor. Although the subject invention relates particularly to a wobble piston compressor, it can be applicable to any piston compressor.
A wobble piston compressor is known to the art. Such a machine using pistons and inlet and outlet reed valves or check valves is known.
U.S. Pat. No. 3,961,868 to Droege, Sr. et al, discloses a wobble piston compressor with a head, or head plate, mounted outlet check valve or reed valve, and an inlet reed valve mounted to a wobble piston; no wear plate is disclosed.
U.S. Pat. No. 4,275,999 to Hetzel et al discloses a wobble piston compressor similar to U.S. Pat. No. 3,961,868; no wear plate is disclosed.
A wobble piston compressor with the inlet valve located on the head is known.
One disadvantage of the wobble piston compressor with a head mounted inlet valve openable inwardly toward the piston, is the fact that during normal operation the inlet valve can make contact with the top surface of the piston causing wear to either or both parts. This can particularly happen when the piston cycle speed is slower than the valve opening speed or where the clearance between the cap of the piston and the undersurface of the head is small.
Under similar conditions, the same wearing effect can occur where the inlet valve is mounted to the wobble piston and opens inwardly toward the head. The valve can make repetitive contact with the head wearing the valve and the head.
The present invention provides a wear pad or wear shield which significantly reduces piston or head and valve wear. Another benefit of the wear shield is noise reduction during operation. In addition, the patch serves as a means of reducing premature failure of the flapper valve. It "cushions" the forces acting on the stainless steel strip.